Establishing Bacterial–Fungal Cross-Kingdom Biofilms for Studying Oral Pathogenesis

Begin with cultures of Streptococcus mutans, an oral pathogenic bacterium, and Candida albicans, an opportunistic fungal pathogen.

Transfer isolated colonies into a nutrient-rich medium and incubate overnight to ensure active growth.

Centrifuge to pellet the cells. Remove the supernatant and resuspend the cells in sterile saline to a defined concentration.

Take a multiwell plate coated with human salivary solution to mimic the oral environment.

Add C. albicans and incubate to allow attachment to the salivary coating. Wash with sterile saline to remove non-adherent cells.

Add heat-inactivated serum and incubate to stimulate hyphal development. Wash off excess serum.

Introduce S. mutans, then sucrose-rich medium and incubate. S. mutans secretes glucosyltransferase, which binds to C. albicans mannans.

This enzyme catalyzes sucrose into glucans on the fungal surface, anchoring bacteria to hyphae and promoting proliferation and matrix formation.

This method yields cross-kingdom biofilms modeling microbial synergy in oral pathogenesis.

Grow S. mutans and C. albicans on blood agar plates at 37 degrees Celsius under aerobic conditions.

Then transfer single colonies of each organism to test tubes fil